Factors related to severe acute asthma in childhood - epidemiologic and clinical aspects

Abstract

To study the epidemiologic and clinical factors related to severe acute asthma in patients hospitalized in pediatric intensive care unit (PICU). STUDY PROFILE: Prospective, epidemiologic. All admissions were observed. All children with severe asthma admitted to PICU-HSL-PUCRS between January, 1994, and December, 1994. Their parents were asked to answer a questionnaire about clinical history and precipitating factors of bronchospasm. Clinical evolution was observed in each patient. 31 children were admitted on 42 occasions to the PICU for the treatment of severe asthma (7.3% of all admissions). The male: female ratio was 1.2:1.0 and the age mean was 25 months. Respiratory viral infections were the main precipitating factor of asthma attacks (74%). Family history of asthma, atopy or tabagism were observed in 97% of the cases. A longer hospitalization period was associated with less than 1 year age (p=0.0005), family history of tabagism (OR= 2.3) and occurrence of pneumonitis (p= 0.03). The long stay in PICU was associated with previous PICU admission (p=0.03), family history of tabagism (OR=2.0) and occurrence of pneumonitis (p=0.02). The main complication observed, especially in patients under 1 year receiving public health care, was pneumonitis, that was diagnosed in 42% of these children. Patients assisted by a private doctor had a shorter hospitalization period and less pneumonitis complication. Mechanical ventilation was necessary in 10% of these patients. There was no death in our series. The incidence of severe acute asthma, associated with long staying in PICU and hospitalization, is related to low age (under 1 year), previous hospitalization due to bronchospasm, family history of asthma, atopy or tabagism, and ineffective medical care. These factors seem related to frequent crises causing more hospitalization indications. These children frequently present pneumonitis during their clinical evolution. Early and aggressive management in general benefit the clinical course of severe acute asthma. The mortality ratio for children with acute asthma who need PICU admissions is small.